1. Field of the Invention
This invention relates to a high frequency positive pressure breathing or oscillatory system, that includes a dual drive system, which oscillatory system moves moderate volumes of a breathing gas in and out of a patient circuit at high frequencies, while at the same time continuously bringing in fresh gas from a source.
2. Description of the Prior Art
Three functions are considered essential to the successful use of a high frequency positive pressure breathing modality. These essential functions are:
(1) Provide a continuous amount of fresh gas to the patient (for removal of CO.sub.2 and to provide O.sub.2). PA1 (2) Actively withdraw gas from the patient during the expiratory phase or portion of a breathing cycle. PA1 (3) Deliver controlled volumes of gas to the patient at high frequency.
A novelty search conducted in the United States Patent and Trademark Office to locate patents relevant to high frequency positive pressure breathing systems resulted in the discovery of the following relevant patents:
______________________________________ U.S. Pat. No. Title Inventor ______________________________________ 2,918,917 Apparatus for Vibrating Portions Emerson of a Patient's Airway 3,349,766 Anesthetizing, Resuscitating, Donofrio and Respiratory Apparatus 3,810,719 Pump for Discharging a Wolthers Predetermined Quantity of Fluid 3,863,082 Permanent Magnet Translational Gillott et al Motor with Auxiliary Electro- magnet 3,923,055 Process and Device for Control- Hammacher ling the Pressure Course of a Respirator 3,993,059 Device for Ventilating a Patient Sjostrand 4,155,356 Respiration Assisting Apparatus Venegas and Method 1,553,379 Improvements in or Relating to (U.K.) Respirators ______________________________________
The fields of search were:
______________________________________ Class Subclass ______________________________________ 92 13.1 and 13.2 128 204.18, 204.21, 204.26, 205.14 and 205.24 417 338, 339, 342, 343, 394, 395, 400 and 403 ______________________________________
Some of these patents disclose systems that perform, in some manner, one or two of the above-noted three essential functions. However, none of these patents teach or even suggest a system which performs all of these three essential functions.